538
(4) Replacing the High Performance model QCPU with the Universal model QCPU
(a) Replacing all single-precision floating-point operation instructions with double-
precision floating-point operation instructions
Single-precision floating-point data occupy two points of word device per data.
On the other hand, four points are required per double-precision floating-point data.
Therefore, all device numbers for storing floating-point data need to be reassigned.
Replacing the floating-point operation [A × B + C] (Changing all floating-point data into double
precision.)
• Device assignment
• Program before replacement
• Program after replacement
Before replacement After replacement
Application Device Data type Application Device Data type
Data A D0 to D1
Floating-point data
(single precision)
Data A D0 to D3
Floating-point data
(double precision)
Data B D2 to D3 Data B D4 to D7
Data C D4 to D5 Data C D8 to D11
Result D6 to D7 Result D12 to D15
Operation is performed using
double-precision floating-point
data.